Electrolytic device and method of making same



Feb. 5,1946. J. B. BRENNAN ELECTROLYTIC DEVICE AND METHOD OF MAKING SAME Filed July 18, 1942 INVENTOR. J'OSFPH E. .B/PE/VNA/V A TTOiP/VEYS mama Feb. 5, 1946 ELECTROLYTIC DEVICE AND OF MAKING SAME METQOD Joseph B. Brennan, Bratenahl, Ohio Application July 18, 1942, Serial No. 451,407 2 Claims. (Cl. 175-315) This invention relates to electrolytic devices and more particularly to containers for electrolytic devices. The invention is described herein,

as applied to electrolytic condensers, but those skilled in the .art will appreciate that the invention is useful in conjunction with other devices and other types of electrolytic devices such as, for example, lightning arresters, rectifiers and-the like. This application is a continuation in part of my copending application Serial No. 289,607, filed August 11, 1939, now Patent No. 2,290,163 issued July 21, 1942.

One of the objects of my invention is to provide electrolytic devices which will be durable and leak proof in service. and which can be manufactured and assembled at low cost. A furthat object is to provide a simple vent and seal construction adapted especially for electrolytic devices, although it is also useful in other environments. Another object is to provide a method of making such a seal. Another object is to provide a method of forming and aging condensers and the like. Another object is to provide electrolytic devices so constructed and arranged that the formation or aging operations can be carried out or completed after partial or complete assembly of the component parts of the device. Further objects and advantages of' my invention will become apparent from the folreference being made to the accompanying drawingwherein:

,Figure 1 is a perspective view .of a condenser made according to my invention.

Figure 2 is a view illustrating the component parts of the condenser shown in Figure 1 before the assembly has been completed.

Figure 3 is a somewhat diagrammatic illustration showing my aging or forming method as applied to a condenser of the type shown in Figure l, but embodyins a vent not shown in Figure 2.

Figure 4 is a side elevation partially in section showing the condenser of Figure 3 after the forming or aging operation has been completed and the condenser sealed.

It has heretofore been the practice to enclose electrolytic condensers of the paste type in containers of a cardboard which must be tarred or waxed to prevent leakage and which in spite of all precautions frequently are found to'be defective. Another type of container ordinarily used in conjunction with condensers of the wet type consists of a fairly heavy gauge aluminum which-'thc anode terminal extends. These containers are generally satisfactory but are expensive to produce and require closures at both the top and bottom thereof.

According to my invention I eliminate the difllculties noted above and produce a low cost yet leakproof and durable container by employing a seal or closure construction which enables me to utilize a light gauge tube of aluminum or other ductile metal, or a tube composed of paper or various plastic materials. Preferably one end of the tube is closed and the other end is open for substantially the full diameter of the tube, although a tube open at both ends may be employed. To close the open end,-or ends, I preferably employ a plug composed of resilient rubber (the term rubber as used throughout the specification and claims is intended to include not only natural rubbers and rubber-like matego rials, but also various synthetic rubbers and rubber-like materials) through which the condenser terminals extend. The light gauge tube may not have sufllcient strength of itself to engage the plug with suflicient force to create the necessary type of seal. To obviate this difliculty,

I employ a seal which is useful and advantageous in other environments, and in which the rubber is compressed into leak proof engagement with the aluminum tube by deforming the tube inwardly and clamping it into deformed position by a clamping device such as a band or wire composed of a heavier or stronger material. The construction embodying the resilient rubber plug also makes possible the use of a simple and efi'ective vent, and permits the circulation of 40 in the drawing wherein the container, which may be light gauge, extruded aluminum tube having a wall thickness of about 0.005 inch for example, is indicated at In. In the specification and claims the terms light gauge" and thin walled are used with respect to the tube or container to define a material of such thinness that it does not of itself possess sufficient strength or rigidity to engage the resilient sealing member or plug with sufllcient force to create the type of seal required by the service for which the device is intended. The open end of the container is closed by a plug ll of resilient rubber through which pass the terminals I2 and ll of the electrode assembly indicated generally at "5..

can having a depending neck portion through The electrode assembly forms no part of the present invention as any ordinary type of electrode may be utilized in conjunction with my container. The assembly illustrated at it may comprise, for example, two electrodes of film forming material rolled up together with suitable spacers to prevent contact between the electrodes, the whole being impregnated with a film maintaining electrolyte which is retained within the container i0. 3

As shown particularly in Figure 2 the component parts of a condenser embodying my invention may be assembledby merely inserting the electrode assembly I! with the container ll, pushing the closure member ii into the open end of the container, and slipping the ring it over the end of the container in the region adjacent the plug ii. Preferably the terminals i2 and I l are passed through slits cut in the plug ii before the parts are positioned in their assembled relationship. It is sometimes desirable to employ separately formed terminals iv! and i4 and weld or otherwise Join them to electrode tabs or terminals i1 and it as indicated at is and 20 rather than to extend the terminals i2 and it into the electrode assembly. If such a construction is employed as shown in the drawing then it is preferable to position the joints is and 20 within the resilient rubber plug ii, the result being that when the plug is compressed onto the terminals the Joint is effectively sealed and protected against corrosion.

After positioning the parts as described above the ring it, which may be composed of steel or other relatively strong metal, or may be of the same material as the tube, 1. e., aluminum in the present case, only of heavier gauge, is deformed inwardly. This operation may be performed by spinning or rolling the ring into the arcuate shape shown in Figures 1 and 3 thus deforming the soft ductile metal of the container iii into intimate sealing engagement with the plug, retaining the container in sealing engagement with the plug, and compressing the plug. By reason of the compression of the material of the plug, an effective seal is madebetween the electrode terminals i2 and I4 and the plug, thus preventing any possible leakage of electrolyte at these points. As illustrated in the drawing the ring it may be provided with means for mounting the device in a support such as, for example, the perforated cars 22 which extend radially outwardly from the ring.

In subjecting electrolytic condensers to their final film forming and aging process it is frequently desirable to circulate the electrolyte around and through the electrodes. This insures proper penetration of the electrolyte throughout the electrode assembly, and assists in dislodging gas bubbles, thereby reducing leakage and preventing defects from occurring in condensers when they are put in service. Also the temperature of the electrolyte may be maintained with the desired range aiding in the production of a film of the desired character. In addition, for some purposes, it is desirable to employ a different electrolyte for the forming or aging operation than is employed when the condenser is in service. Heretofore, a different electrolyte could not be employed with the usual compact type of condenser except by carrying out the forming and aging operations before the condenser was finally assembled. This necessitated handling of the formed or partly formed electrode and the handling frequently resulted in increased leakage in the condenser. According to my present invention the forming and aging operations can be carried out with the electrodes assembled within the container, yet it is possible to circulate the electrolyte during these operations or to use one electrolyte for the forming and aging and then to supply a diiferent electrolyte for service if desired.

These operations may be accomplished very conveniently in the manner illustrated in Figure 3. As there shown the electrodes [5, terminals I2 and I4, plug ii and ring it may all be assembled with the container i0. Preferably, but not necessarily, prior to deforming the ring into clamping engagement with the container, small openings as at "and 30 are pierced through the plug Ii, preferably without removing any material therefrom, and small tubes or needles II and 32 inserted through the openings into communication with the interior of the container il. Electrolyte may then be pumped into the container through the tube 3 i, for example, while the electrolyte flows out through the tube 32.

The terminals i2 and il may be connected to a suitable source of electromotive force as by the conductors I! and N and in this manner the condenser or other electrolytic device may be subjected to the desired film forming and aging operations while electrolyte is being circulated through the condenser by means of the tubes 3i and I! projecting through the plug I l. Obviously the temperature of the circulating electrolyte can be controlled by suitable means such as coils, for example, disposed externally of the condenser. Thus the electrolyte can be either heated or cooled to the desired temperature. If it is desired to use one electrolyte for forming or aging and another electrolyte in service, the forming electrolyte may be evacuated by means of gas pressure or vacuum, the condenser being inverted; or the service electrolyte may be circulated after the forming or aging operation is completed, and this circulation may be continued until substantially all of the forming or aging electrolyte is removed from the condenser.

In order to provide a vent, if one is required, a small tube 35 may be inserted through the rubber plug II as illustrated in Figures 3 and 4. The opening for the tube preferably is merely pierced without removing any material of the plug, and the tube may either be provided with a fusible wax core or may be of such small diameter that it will substantially prevent the escape of liquid from the interior of the condenser while permitting the escape of gas. The compression of the plug by the ring IE will effectively seal the plug against the exterior of the vent tube 35. A vent is not essential for some types of condensers, and no vent is illustrated in Figures 1 and 2. Otherwise, the condenser shown in Figures 3 and 4 is identical with that shown in Figures 1 and 2.

After the aging process has been completed the condenser may be made ready for shipment and sale merely by removing the tubes 3i and 32 and then compressing the ring iii inwardl to deform the container it into intimate engagement with the plug ii and to compress the plug. Obviously, if the ring was compressed prior to forming the film, no further deformation will be necessary as the compressive stresses in the rubber will result in the immediate sealing of the openings as soon as the tubes are removed. The compression of the plug results in completely closing and effectively sealing the openings 29 and 30 through which the tubes 3| and 32 were inserted. The

. 4 aseaeeo 3 compression of the plug is preferably such that after the tubes 3| and 32 are removed, the openings are almost invisible, the closed openings being indicated diagrammatically by dots and lines,

respectively, in Figures 1 and 4. By this method, 5

the aging process has been completed the condenser can be sealed up without requiring any handling of the electrodes thus eliminating any possibility of contamination of the condenser.

From the foregoing it will be evident that I have provided a simple and economical construction for devices such as electrolytic condensers whereby light gauge tubes can be utilized as containers. By my invention an effective seal can be produced between a light gauge tubular member and a resilient member disposed therewithin, 0

and the resilient member can be compressed and sealed against members such as terminals, vents, and the like passing through it. My construction lends itself to easy and economical assembly methods and condensers made according, to my invention can be formed or aged with circulating electrolyte, with the electrodes in their final assembled relationship'and without requiring any additional handling of the electrodes, thus obviating the possibility of any subsequent contamination of the electrolyte or electrodes, or damage to the electrodes. The temperature of the electrolyte may be controlled during formation or aging and different electrolytes may be employed, all

without requiring any subsequent handling or dis- 5 turbance of the electrodes. Thu the final forming or aging operation (sometimes called healing" or curing) can be carried out under most advantageous conditions to produce a condenser having low leakage losses, and the condenser is 4 completed without disturbance to the electrodes thereafter.

In the foregoing specification I have described preferred forms of my invention merely by way of example and with no intention that my patent a should be limited to the precise embodiments disclosed herein. Various modifications and changes can be made in the constructions and methods shown and described herein, and the invention can be adapted to other devicm without departing from the spirit and scope of my invention. Therefore it is to be understood that my patent is not limited to the forms illustrated and'described herein or in any manner other than by the appended claims when given the range of equiv alents to which my patent may be entitled.

Iclaim:

1. In the manufacture of electrolytic condensers and the like of the type embodying a container having an opening therein. an electrode disposed in the container, a soft rubber closure member for the container and a terminal for the electrode passing through said closure member, which includes the steps of placing the electrode within the container, positioning the closure member in the opening of the container with the terminal extending therethrough, forming two openings through said member, inserting tubes through said openings, circulating an electrolyte within said container through said tubes and at the same time subjecting the condenser to an electrolytic aging process, thereafter withdrawing said electrolyte from the container and supplying another electrolyte to said container, withdrawing said tubes from said member, and subjecting said member to suillcient compressive force to close said openings.

2. In the manufacture of electrolytic devices of the type having a container for electrolyte and an electrode disposed therein, the process which includes the steps of disposing the electrode within the container, connecting the container to a fluid circulating system, connecting the device into an electric circuit and causing a current to flow therethrough to thereby subject the device to an electrolytic aging or filming operation, circulating one electrolyte within the container during at least part of the aging or fllm-forming'operation, thereafter withdrawing said first electrolyte and supplying another electrolyte to said container, and finally disconnecting the container from the fluid circulating system and sealing the container without disturbing the assembled relationship of the parts or removing them from the container.

JOSEPH B. BRENNAN. 

